Our product range (PP pipes and fittings) includes different types of polymers: The homopolymers (PP-H), which are composed exclusively of propylene molecules, and the two different copolymers in which ethylene monomers are incorporated in blocks (polypropylene block copolymer, PP-B) or randomly distributed (polypropylene random copolymer, PP-R). Our pipes are made of PP-H and our fittings of PP-R as standard. Both types are highly heat stabilized and ideally suited for the production of piping systems subject to pressure. The various types of propylene can be joined using all common welding methods.
Impact strength is temperature-dependent and increases with rising temperature or decreases with falling temperature. PP-R has better impact strength than PP-H.
Application examples:
PP homopolymers
PP random copolymers
Delivery program:
Temperature | SDR 11 | SDR 17,6 |
---|---|---|
20 °C | 12,5 | 7,5 |
40 °C | 10 | 6,0 |
60 °C | 7,5 | 4,5 |
Polypropylene is generally not permanently resistant to high-energy radiation. The impact of high-energy radiation to polypropylene may result in a temporary increase in strength due to crosslinking of the molecular structure. However, permanent exposure to radiation causes the molecular chains to break, resulting in a considerable reduction in strength due to damage to the material. This behavior must be taken into account by a reduction factor, which must be determined experimentally.
Pipes made of grey polypropylene are not UV-stabilized and must therefore be protected accordingly. If effective protection is not possible, outdoor use is still possible in accordance with DVS 2210-1. Under UV radiation, an oxide layer forms on the pipe surface, which can be absorbed by a calculated wall thickness surcharge. According to DVS, this wall thickness surcharge should be at least 2 mm. The service life is limited to 10 years.
The composition of polypropylene complies with the relevant food regulations (according to BGA and KTW guidelines). Furthermore, PP pipes and fittings have been tested and approved for drinking water suitability.
In principle, PP is considered resistant to a wide range of acids and alkalis. Alkaline solutions, phosphoric acid, hydrochloric acid are only a few of the substances to which PP is resistant. PP, on the other hand, is only conditionally resistant to hydrocarbons, as it can lead to swelling of >3%. As a result, PP is less suitable against gasoline. The same applies to free chlorine and ozone. Due to its high temperature resistance, PP is considered ideal for use in pickling plants, the chemical industry as well as highly aggressive wastewater. However, the chemical resistance must always be considered in conjunction with the operating temperature, operating pressure and any external stresses, as these may result in limitations. The chemical resistance list is intended as a first indication. Specific applications can be clarified with our technical department.
We are happy to advise you